Automatic target selection

ABSTRACT

A method of identifying targets for monitoring includes: obtaining a user-defined filter map, the user-defined filter map having one or more filter rules for matching against network traffic when the user-defined filter map is used by a network system to process the network traffic. and determining a set of one or more targets by a processing unit based at least in part on the user-defined filter map, wherein the processing unit comprises a target selection module configured to access a list of available targets from a database, and select the one or more targets from the list of available targets based at least in part on the user-defined filter map.

FIELD

This application relates generally to network traffic monitoring, andmore specifically, to systems and methods for network trafficmonitoring.

BACKGROUND

For network traffic monitoring, a user may need to identify certaintargets. A target in this context is a network component for which thenetwork monitoring is performed. For example, if a user wants to monitornetwork traffic going to a certain target, then the user may identifysuch target in the monitoring session. The task performed by the user toidentify every target that needs to be monitored may become tedious,especially when there is a very large number of potential targets. Also,such a task may need to be repeated every time a new rule or a new mapis created. In addition, if new targets of interest appear in themonitoring domain, they may need to be manually identified by the user,so that the user can associate the new targets with the map, beforethese new targets can be monitored.

SUMMARY

A method of identifying targets for monitoring includes: obtaining auser-defined filter map, the user-defined filter map having one or morefilter rules for matching against network traffic when the user-definedfilter map is used by a network system to process the network traffic;and determining a set of one or more targets by a processing unit basedat least in part on the user-defined filter map, wherein the processingunit comprises a target selection module configured to access a list ofavailable targets from a database, and select the one or more targetsfrom the list of available targets based at least in part on theuser-defined filter map.

Optionally, the target selection module is configured to select the oneor more targets from the list of available targets based on:

$\mspace{20mu} {C = \{ {\begin{matrix}{\mspace{14mu} \begin{matrix}{{{subset}\mspace{14mu} {of}\mspace{14mu} V\mspace{14mu} {associated}\mspace{14mu} {with}\mspace{14mu} \text{?}L\; 1} - {L\; 3}} \\{{filter}\mspace{14mu} {component}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )}\end{matrix}} \\V\end{matrix},\mspace{20mu} {R = \text{?}},\mspace{20mu} {{{and}\mspace{20mu} F} = {\text{?}\text{?}\text{indicates text missing or illegible when filed}}}} }$

wherein V represents the set of available targets, R represents a targetset for a rule comprising m filter components, and F represents a targetset for a map having n rules.

Optionally, the target selection module is configured to select the oneor more targets from the list of available targets also based on aninclusion set I defined as:

$\mspace{20mu} {\text{?} = \{ {\begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {included}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{V\; ({otherwise})}\end{matrix}\text{?}\text{indicates text missing or illegible when filed}} }$

Optionally, the target selection module is configured to select the oneor more targets from the list of available targets also based on anexclusion set E defined as:

$E = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {excluded}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{\varnothing \; ({otherwise})}\end{matrix} $

Optionally, the one or more targets constitute a target set T defined asT=(F∩I)−E.

Optionally, the targets comprise a virtual machine (VM).

Optionally, the targets comprise a vNIC.

Optionally, the act of determining the set of one or more targetscomprises determining a first set of targets that are possible source(s)and/or recipient(s) of packets satisfying any of the one or more filterrules in the user-defined filter map.

Optionally, the user-defined filter map comprises a first filter rulehaving first multiple filter components, and wherein the act ofdetermining the set of one or more targets comprises determining a firstset of targets by the processing unit that are possible source(s) and/orrecipient(s) of packets satisfying all of the first multiple filtercomponents of the first filter rule.

Optionally, the user-defined filter map comprises a second filter rulehaving second multiple filter components, and wherein the act ofdetermining the set of one or more targets further comprises determininga second set of targets by the processing unit that are possiblesource(s) and/or recipient(s) of packets satisfying all of the secondmultiple filter components of the second filter rule.

Optionally, the method further includes: obtaining information regardingan inclusion set; and determining a second set of targets based on theinformation regarding the inclusion set; wherein the set of one or moretargets is determined based on: (the first set of targets)∩(the secondset of targets).

Optionally, the method further includes: obtaining information regardingan exclusion set; and determining a third set of targets based on theinformation regarding the exclusion set; wherein the set of one or moretargets is determined based on: ((the first set of targets)∩(the secondset of targets))−(the third set of targets).

Optionally, the obtained user-defined filter map comprises a newlycreated filter rule, and the act of determining the set of one or moretargets is performed by the processing unit in response to the newlycreated filter rule.

Optionally, the obtained user-defined filter map comprises a modifiedfilter rule resulted from a modification of an existing filter rule, andthe act of determining the set of one or more targets is performed bythe processing unit in response to the modified filter rule.

Optionally, one of the one or more filter rules comprises one or morefilter components, the one or more filter components comprisinginformation regarding a switch port, a MAC address, a VLAN identifier,an ethertype, an IP address, a wildcard, or any combination of theforegoing.

An apparatus for identifying targets for monitoring includes: anon-transitory medium for storing a user-defined filter map, theuser-defined filter map having one or more filter rules for matchingagainst network traffic when the user-defined filter map is used by anetwork system to process the network traffic; and a processing unitconfigured for determining a set of one or more targets based at leastin part on the user-defined filter map; wherein the processing unitcomprises a target selection module configured to determine the set ofone or more targets by accessing a list of available targets from adatabase, and selecting the one or more targets from the list ofavailable targets based at least in part on the user-defined filter map.

Optionally, the target selection module is configured to select the oneor more targets from the list of available targets based on:

$\mspace{20mu} {C = \{ {\begin{matrix}{\mspace{14mu} \begin{matrix}{{{subset}\mspace{14mu} {of}\mspace{14mu} V\mspace{14mu} {associated}\mspace{14mu} {with}\mspace{14mu} \text{?}L\; 1} - {L\; 3}} \\{{filter}\mspace{14mu} {component}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )}\end{matrix}} \\V\end{matrix},\mspace{20mu} {R = \text{?}},\mspace{20mu} {{{and}\mspace{20mu} F} = {\text{?}\text{?}\text{indicates text missing or illegible when filed}}}} }$

wherein V represents the set of available targets, R represents a targetset for a rule comprising m filter components, and F represents a targetset for a map having n rules.

Optionally, the target selection module is configured to select the oneor more targets from the list of available targets also based on aninclusion set I defined as:

$\mspace{20mu} {\text{?} = \{ {\begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {included}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{V\; ({otherwise})}\end{matrix}\text{?}\text{indicates text missing or illegible when filed}} }$

Optionally, the target selection module is configured to select the oneor more targets from the list of available targets also based on anexclusion set E defined as:

$E = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {excluded}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{\varnothing \; ({otherwise})}\end{matrix} $

Optionally, the one or more targets constitute a target set T defined asT=(F∩I)−E.

Optionally, the targets comprise a virtual machine (VM).

Optionally, the targets comprise a vNIC.

Optionally, the processing unit is configured for determining the set ofone or more targets by determining a first set of targets that arepossible source(s) and/or recipient(s) of packets satisfying any of theone or more filter rules in the user-defined filter map.

Optionally, the user-defined filter map comprises a first filter rulehaving first multiple filter components, and wherein the processing unitis configured for determining the set of one or more targets bydetermining a first set of targets by the processing unit that arepossible source(s) and/or recipient(s) of packets satisfying all of thefirst multiple filter components of the first filter rule.

Optionally, the user-defined filter map comprises a second filter rulehaving second multiple filter components, and wherein the processingunit is configured for determining the set of one or more targetsfurther by determining a second set of targets by the processing unitthat are possible source(s) and/or recipient(s) of packets satisfyingall of the second multiple filter components of the second filter rule.

Optionally, the processing unit is further configured for: obtaininginformation regarding an inclusion set; and determining a second set oftargets based on the information regarding the inclusion set; whereinthe processing unit is configured to determine the set of one or moretargets based on: (the first set of targets)∩(the second set oftargets).

Optionally, the processing unit is further configured for: obtaininginformation regarding an exclusion set; and determining a third set oftargets based on the information regarding the exclusion set; whereinthe processing unit is configured to determine the set of one or moretargets based on: ((the first set of targets)∩(the second set oftargets))−(the third set of targets).

Optionally, the obtained user-defined filter map comprises a newlycreated filter rule, and the processing unit is configure fordetermining the set of one or more targets in response to the newlycreated filter rule.

Optionally, the obtained user-defined filter map comprises a modifiedfilter rule resulted from a modification of an existing filter rule, andthe processing unit is configured for determining the set of one or moretargets in response to the modified filter rule.

Optionally, one of the one or more filter rules comprises one or morefilter components, the one or more filter components comprisinginformation regarding a switch port, a MAC address, a VLAN identifier,an ethertype, an IP address, a wildcard, or any combination of theforegoing.

An apparatus includes a non-transitory medium storing a set ofinstructions, an execution of which by a processing unit causes a methodof identifying targets for monitoring to be performed, the methodcomprising: obtaining a user-defined filter map, the user-defined filtermap having one or more filter rules for matching against network trafficwhen the user-defined filter map is used by a network system to processthe network traffic; and determining a set of one or more targets by theprocessing unit based at least in part on the user-defined filter map,wherein the processing unit comprises a target selection moduleconfigured to access a list of available targets from a database, andselect the one or more targets from the list of available targets basedat least in part on the user-defined filter map.

Other and further aspects and features will be evident from reading thefollowing detailed description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of embodiments, in whichsimilar elements are referred to by common reference numerals. Thesedrawings are not necessarily drawn to scale. In order to betterappreciate how the above-recited and other advantages and objects areobtained, a more particular description of the embodiments will berendered, which are illustrated in the accompanying drawings. Thesedrawings depict only typical embodiments and are not therefore to beconsidered limiting of its scope.

FIG. 1 illustrates a network in accordance with some embodiments;

FIG. 2 illustrates another network in accordance with some embodiments;

FIG. 3 illustrates a fabric manager that includes a target selectionmodule in accordance with some embodiments;

FIG. 4 illustrates a method of identifying targets for a network system;

FIG. 5 illustrates an example of automatic target selection; and

FIG. 6 illustrates a specialized processing system with whichembodiments described herein may be implemented.

DESCRIPTION OF THE EMBODIMENTS

Various embodiments are described hereinafter with reference to thefigures. It should be noted that the figures are not drawn to scale andthat elements of similar structures or functions are represented by likereference numerals throughout the figures. It should also be noted thatthe figures are only intended to facilitate the description of theembodiments. They are not intended as an exhaustive description of theinvention or as a limitation on the scope of the invention. In addition,an illustrated embodiment needs not have all the aspects or advantagesshown. An aspect or an advantage described in conjunction with aparticular embodiment is not necessarily limited to that embodiment andcan be practiced in any other embodiments even if not so illustrated, ornot so explicitly described.

General Description

Virtual machine (VM) traffic monitoring requires an end-user to performthe following tasks as part of the workflow for initiating a monitoringsession: (1) Identify targets desired to be monitored, (2) Definefilters, and (3) Specify actions.

A target in this context may be a VM or a virtual network interface card(vNIC) belonging to a VM. A target may be a source of packets, or arecipient of packets. User-defined filters may be expressed as rules ina map. A rule specifies filter components (e.g., L1, L2, L3, L4) thatmust be satisfied simultaneously. A map is a collection of one or morerules and some associated actions, which get executed whenever any rulein the map has a match. Typical actions involve packet manipulation(e.g. truncation), forwarding (e.g. tunnel to specified destination),packet dropping, or any combination of the foregoing.

Automatic Target Selection (ATS) simplifies the user workflow byeliminating the first step. In ATS, the targets to be monitored areinferred from the specified filters. The user, however, has the optionto guide the selection process, if necessary.

An ATS algorithm will now be described. In the ATS algorithm, targetsare inferred from filters. In particular, ATS is based on the idea thatonly those targets whose ingress/egress traffic can potentially resultin a match with the user-defined filters need to be monitored (while theremaining targets can be safely ignored). The target selection processtherefore involves deriving the set of all such targets for a given mapand is carried out as follows.

1. A filter component set C is created for each of the m supported L1-L3filter components.

$C = \{ {\begin{matrix}{\mspace{14mu} \begin{matrix}{{{subset}\mspace{14mu} {of}\mspace{14mu} V\mspace{14mu} {associated}\mspace{14mu} {with}\mspace{14mu} \text{?}L\; 1} - {L\; 3}} \\{{filter}\mspace{14mu} {component}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )}\end{matrix}} \\V\end{matrix}\text{?}\text{indicates text missing or illegible when filed}} $

wherein V denotes the universal set (which consists of all targetswithin the monitoring domain that are currently listed in theinventory). Thus, the filter component set C represents a subset of theavailable targets that satisfies a certain filter component if thefilter component is specified by a user.

Only local L1-L3 filter components are considered when looking forsubsets of V because remote filter components are not associated withthe (local) monitoring domain. Also, L4 filter components are ignored asthey do not help in identifying targets. Here are some examples of thefilter components that may be considered:

-   -   L1—Switch port    -   L2—MAC address, VLAN id, ethertype    -   L3—IP address

2. Since all the filter components in a rule must be satisfiedsimultaneously, the filter set R for a rule is given by:

  R = ? ?indicates text missing or illegible when filed

In the above equation, “∩” is an intersection function. Note that theintersection of A and B, denoted A∩B, is the set of all items that aremembers of both A and B. Thu, the filter set R represents a set oftargets that satisfy all of the filter components in a certain rule.

3. Because a map is considered to have a match if any of its rules has amatch, the filter set F for a map with n rules is given by:

$F = {\overset{n}{\bigcup\limits_{j = 1}}R_{j}}$

In the above equation, “∪” is an union function. Note that the union ofA and B, denoted A∪B, is the set of all items that are members of eitherA or B.

In some embodiments, the ATS may allow the user to guide the targetselection process, if necessary, by creating special inclusion and/orexclusion sets.

The inclusion set contains only those targets that should be consideredby ATS. The user can define it by identifying specific targets or byusing an appropriate filter. Inclusion sets may be saved in a library(e.g., a non-transitory medium) for later use. The inclusion set I maybe defined as follows:

$I = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {included}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{V({otherwise})}\end{matrix} $

The exclusion set contains targets that should not be considered by ATS.The user can define it by identifying specific targets or by using anappropriate filter. Exclusions sets may be saved in a library (e.g., anon-transitory medium) for later use. The exclusion set E may be definedas follows:

$E = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {excluded}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{\varnothing ({otherwise})}\end{matrix} $

wherein Ø denotes the empty set.

The (final) target set for a map is based on its filter set andappropriate inclusion set I and exclusion set E, as follows:

T=(F∩I)−E

In the above equation, “−” is a difference function. Note that thedifference of A and B, denoted A−B, is the set of all items that aremembers of A but not members of B.

The ATS algorithm may be re-run whenever the inventory of targets isupdated. This allows addition of new target(s) and/or changes in theexisting target(s) be detected.

ATS can overcome the following disadvantages associated with manualselection of targets. The manual selection process to select targets canbe tedious, especially when dealing with a very large number ofpotential targets. The manual selection technique will require a user tomanually repeat the process every time a new map is created. Also, whennew targets of interest appear in the monitoring domain, they have to bemanually identified by the user and associated with a map, before theycan be monitored.

One advantage of the manual target selection process is that the userhas complete control over target selection. However, ATS can adequatelymatch this capability because it allows the user to guide the selectionprocess, if necessary.

Furthermore, ATS offers the following advantages. The selection processensures that only the relevant targets (whose ingress/egress networktraffic can potentially match rules in the map) are selected formonitoring. In the case where the user supplied inclusion and/orexclusion sets are incompatible with the filter set derived from themap, the system can flag a warning. In the manual target selectionschemes, such incompatibilities cannot be easily detected.

DETAILED DESCRIPTION

Before ATS is described, an example of the network environment in whichthe ATS may be implemented/used is first described. As discussed, ATSmay be employed to determine targets for network traffic monitoring.Network traffic in a network is transmitted from a sender for anintended recipient through a traffic production network. VM trafficmonitoring involves capturing packets from the traffic productionnetwork (e.g., packets entering and/or leaving VMs) and delivering themto appropriate tools for analysis. One way to achieve this, withoutadversely affecting VM traffic patterns in the traffic productionnetwork, is to mirror packets associated with certain VMs to anout-of-band network where they can be processed and eventually forwardedto the respective tools that perform analysis to monitor networktraffic. In accordance with some embodiments, an auxiliary network isprovided for this purpose. This auxiliary network (called “SoftwareDefined Visibility Fabric”) is a policy driven network of chainedservice nodes. Each service node represents a packet processing stationthat can filter, manipulate and dispatch network packets. The auxiliarynetwork is built by linking these service nodes together, e.g., using IPtunnels such as GRE, VxLAN, etc. The ATS described herein may beemployed to determine targets for the auxiliary network for networktraffic monitoring.

FIG. 1 illustrates a network 10 in accordance with some embodiments. Thenetwork 10 is an auxiliary network that is implemented to capturepackets from a traffic production network. As shown in the figure, theauxiliary network 10 includes a virtual switch 11 implemented in a host12, and a virtual machine (VM) 16 supported by the host 12. In theillustrated example, the host 12 that implements the virtual switch 11is also the same host that supports the VM 16. In other examples, theremay be one host 12 implementing the virtual switch 11, and another host12 supporting the VM 16. As shown in the figure, the host 12 alsosupports multiple virtual machines VMs 14, but the VMs 14 are not a partof the auxiliary network. The network 10 also includes a physicalnetwork device 18 communicatively coupled to the host 12 and/or the VM16. The network device 18 is configured to communicate with one or moretools 20. In some cases, each tool 20 may be a network monitoring toolconfigured to analyze packets for network monitoring. In other cases,each tool 20 may be any of other types of packet processing tools. TheVMs 14 may be configured to run different applications to processpackets and/or to perform other types of tasks. The VM 16 is configuredto perform packet processing to pass packets downstream for analysis bythe tool(s) 20. As shown in the figure, a Software Defined Networking(SDN) controller 22 may be configured to control the behavior of thevirtual switch 11 and the VM 16.

The VM 16 and the network device 18 are parts of an auxiliary networkconfigured to obtain packets from a production network, and to pass thepackets to the tool(s) 20 for analysis. Thus, the VM 16 and the networkdevice 18 are not parts of the production network. The virtual switch 11is special because it can straddle the boundary between the productionnetwork and the auxiliary network. Thus, it is a part of the productionnetwork. If the virtual switch is used as a P0 node by the visibilityfabric, then it is also a part of the auxiliary network. Not all virtualswitches may be used as a P0 node. However, those that meet certaincriteria of a visibility fabric service node (e.g., those that arecapable of filtering, manipulation, and forwarding packets) can be usedas a P0 node.

In the illustrated embodiments, the virtual switch 11, the VM 16, andthe network device 18 are respective service nodes P0, P1, P2, eachoffering varying levels of capability, as follow:

-   -   P0 Node Host-level (advanced) virtual switch 11 (lowest        capability)    -   P1 Node Virtual monitoring appliance 16 (intermediate        capability)    -   P2 Node Physical monitoring appliance 18 (highest capability)        In particular, each service node is capable of providing some        degree of packet filtering, packet manipulating, and packet        forwarding services. The P0 service node provides the lowest        degree of packet filtering, packet manipulating, and packet        forwarding services. The P1 service node provides an        intermediate degree of packet filtering, packet manipulating,        and packet forwarding services. The P2 service node provides the        highest degree of packet filtering, packet manipulating, and        packet forwarding services.

The P0 nodes straddle the boundary between a traffic production network(where normal network traffic, such as VM traffic, is flowing) and theauxiliary network (Software Defined Visibility Fabric). Their use helpseliminate unwanted traffic closer to the VMs being monitored, therebyfreeing up precious bandwidth and reducing processing cycles consumed byother nodes. The P1 nodes may aggregate traffic originating from severalP0 and P1 nodes, and offer some advanced packet manipulationcapabilities. Similarly, P2 nodes may aggregate traffic from several P0,P1 and P2 nodes and provide the highest levels of capacity, performanceand packet manipulation capabilities. In some cases, the auxiliarynetwork may also include P3 node representing a tool 20.

The network device 18 is configured to receive packets, and pass thepackets to one or more tools 20. In some cases, the network device 18may be configured to receive normal packets (e.g., packets not from avirtualized network), as well as virtualized packets (e.g., packets withtunnel format that includes encapsulation of the original packetsresulted from virtualization technology). In other cases, the networkdevice 18 may be configured to receive only virtualized packets. Also,in some cases, the network device 18 may be any switch module thatprovides packet transmission in accordance with a pre-determinedtransmission scheme. In some embodiments, the network device 18 may beuser-configurable such that packets may be transmitted in a one-to-oneconfiguration (i.e., from one network port to an instrument port). Asused in this specification, the term “instrument port” refers to anyport that is configured to transmit packets to a tool (e.g., tool 20),wherein the tool may be a non-pass through device (i.e., it can onlyreceive packets intended to be communicated between two nodes, andcannot transmit such packets downstream), such as a sniffer, a networkmonitoring system, an application monitoring system, an intrusiondetection system, a forensic storage system, an application securitysystem, etc., or the tool may be a pass-through device (i.e., it canreceive packets, and transmit the packets back to the device 100 afterthe packets have been processed), such as an intrusion preventionsystem. In other embodiments, the network device 18 may be configuredsuch that the packets may be transmitted in a one-to-many configuration(i.e., from one network port to multiple instrument ports). In otherembodiments, the network device 18 may be configured such that thepackets may be transmitted in a many-to-many configuration (i.e., frommultiple network ports to multiple instrument ports). In furtherembodiments, the network device 18 may be configured such that thepackets may be transmitted in a many-to-one configuration (i.e., frommultiple network ports to one instrument port). In some embodiments, theone-to-one, one-to-many, many-to-many, and many-to-one configurationsare all available for allowing a user to selectively configure thenetwork device 18 so that the packets (or certain types of packets) arerouted according to any one of these configurations. Also, in someembodiments, the network device 18 may be an “out-of-band” networkdevice, which is configured to obtain packets and pass them to a tool orto a network that is different from that associated with the originalintended destination of the packets. Thus, the network device 18 is nota part of the underlying network that performs packet production.

As shown in the figure, a fabric manager 100 may be provided, that isconfigured to communicate with the SDN controller 22 and the networkdevice 18. In some cases, the fabric manager 100 may integrate with theSDN controller 22 through a plug-in 24. For example, in some cases, in aSDN enabled datacenter supporting virtualized workloads, the host-levelvirtual switches 11 may be under the control of the SDN controller 22.Since these switches 11 serve as service nodes in the SDN fabric, thefabric manager 100 may be integrated with the SDN controller 22 usingthe plug-in 24. The upper-half of the plug-in 24 may export an API thatis specifically designed to satisfy the needs of the fabric manager 100.The lower-half of the plug-in 24 may be controller specific (e.g.,different lower-halves of the plug-in 24 may be implemented fordifferent controllers). In such an environment, it is possible for thefabric manager 100 to also manage the VMs 16 and the network devices 18using the SDN controller 22, provided they are compatible with thecontroller's 22 Control-Data-Plane-Interface. If not, the fabric manager100 may directly manage the VMs 16 and the network devices 18. In othercases, the plug-in 24 may not be needed.

It should be noted that the auxiliary network 10 is not limited to theexample illustrated in FIG. 1, and that the auxiliary network 10 mayhave other configurations in other examples. For example, as shown inFIG. 2, the auxiliary network 10 may include multiple virtual switches11 a-11 c at multiple hosts 12 a-12 c. The virtual switch 11 a is not apart of the auxiliary network 10. The virtual switches 11 b, 11 c areparts of the auxiliary network 10, and therefore they may be consideredservice nodes P0. As shown in the figure, the host 12 a supports VMs 14a-14 c, the host 12 b supports VM 14 d, and the host 12 c supports VMs14 e-14 g. However, the VMs 14 are not parts of the auxiliary network.The network 10 may also include multiple VMs 16 a, 16 b. The VM 16 a isassociated with the host 12 a, and the VM 16 b is associated with thehost 12 b. Although one network device 18 is shown, in other examples,there may be multiple network devices 18, each of which configured tocommunicate with one or more tools 20.

FIG. 2 shows two examples of virtualization management layer (orinfrastructure), one being vCenter 26 and the other being OpenStack 28.Although only one vCenter 26 and one openstack 28 are shown, in otherexamples, there may be multiple vCenters 26 and/or multiple openstacks28. As shown in FIG. 2, there is a SDN controller 22, which communicateswith various components in the network 10. The SDN controller 22 maycommunicate with virtual switch(es) 11 implemented at one or more of thehosts 12 a, 12 b, 12 c, either directly, or indirectly through thevCenter 26 and/or the openstack 28. The SDN controller 22 may alsocommunicate with the VMs 16 a, 16 b.

As discussed, the virtual switch 11, the VM 16, and the network device18 are parts of an auxiliary network configured to obtain packets from aproduction network, and to pass packets to the tool(s) 20 for analysis.There are various paths for passing the packets downstream to thetool(s) 20. For example, in a first scenario, a packet may betransmitted by the virtual switch 11 to the VM 16, and then from the VM16 to the network device 18. The network device 18 then passes thepacket to the tool(s) 20. In a second scenario, a packet may betransmitted by the virtual switch 11 to the VM 16, and the VM 16 maythen pass the packet directly to the tool(s) 20 without going throughthe network device 18. In a third scenario, the virtual switch 11 maypass the packet to the network device 18 without going through the VM16, and the network device 18 then passes the packet to the tool(s) 20.In a fourth scenario, the virtual switch 11 may pass a packet directlyto tool(s) 20 without going through the VM 16 and the network device 18.

In accordance with some embodiments, ATS may be implemented using thefabric manager 100. During use, a target selection module in the fabricmanager 100 determines targets for a user based on a filter map of oneor more filter rules provided by the user. A target in this context maybe a VM, a vNIC, or any of other components having packets that aredesired to be monitored.

B. Automatic Targets Selection

In some cases, for monitoring network traffic, a user may perform thefollowing tasks for initiating a monitoring session: (1) identifytargets desired to be monitored, (2) define filters, and (3) specifyactions. A target in this context is a network component for which thenetwork monitoring is performed. For example, if a user wants to monitornetwork traffic going to a certain target, then the user may identifysuch target in the monitoring session. By means of non-limitingexamples, a target may be a VM, a vNIC, or any network component that isdesired to be monitored.

The user-defined filters may be expressed as rules (filter rules) in amap (filter map). A rule may specify filter components (e.g., L1-L4)that are to be compared with packets to see if there is a match. Apacket is considered as matching a rule if all of the filter componentsin the rule are met by the packet. In some cases a map may have onerule. In other cases, a map may have multiple rules.

The action specified by the user may be any action that is to beperformed by one or more network components (e.g., by host 12, VM 16,network device 18, etc.) if a packet matches any rules in a map definedby the user. By means of non-limiting examples, an action may be anypacket manipulation (e.g., tagging, truncation, etc.), packet forwarding(e.g., tunnel to a certain specified destination), etc. In some cases,the actions associated with a rule/map are executed whenever any rule inthe map has a match. The search for a match may be performedsequentially or in parallel. Also, in some implementations, the searchmay be terminated after the first match. In addition, in some cases, thespecified action(s) may be considered to be a part of the map.

The task performed by the user to identify every target that needs to bemonitored may become tedious, especially when there is a very largenumber of potential targets. Also, such a task may need to be repeatedevery time a new map with multiple rules is created. In addition, if newtargets of interest appear in the monitoring domain, they may need to bemanually identified by the user, so that the user can associate the newtargets with the map, before these new targets can be monitored.Accordingly, it may be desirable to provide an automatic targetselection for the user. In some embodiments, such may be accomplished bythe fabric manager 100 that automatically selects certain targets for auser.

In some cases, the fabric manager 100 providing the automatic targetselection may be implemented using software that is run on a device. Insuch cases, the device running the automatic target selection softwarebecomes a specialized device. By means of non-limiting examples, thedevice may be a computer, a laptop, a server, a tablet, an iPad, aphone, a network device, or any of other devices that is capable ofperforming communication.

FIG. 3 illustrates a fabric manager 100 that is configured to provideautomatic target selection. As shown in the figure, the fabric manager100 includes a processing unit 102 and a non-transitory medium 104communicatively coupled to the processing unit 102. The fabric manager100 also includes a communication interface 106 for receivinginformation from a user. In other cases, there may be multiplecommunication interfaces for receiving information from multiple users.The fabric manager 100 also includes a network interface 108 configuredto communicate with a controller (e.g., the SDN controller 22), and anetwork interface 110 configured to communicate with a network device(e.g., the network device 18). Although only one network interface 108and one network interface 110 are shown, in other examples, the fabricmanager 100 may include multiple network interfaces 108 forcommunicating with multiple controllers 22, and/or multiple networkinterfaces 110 for communicating with multiple network devices 18. Inother embodiments, two or more of the network interfaces 106, 108, 110may be combined and be implemented as a single network interface. In theillustrated example, the processing unit 102 and the non-transitorymedium 104 are accommodated in a housing 112 of the fabric manager 100.The housing 112 allows the fabric manager 100 to be carried,transported, sold, and/or operated as a single unit. Alternatively, thenon-transitory medium 104 may be external to the housing 112. Forexample, the non-transitory medium 104 may be one or morestorages/databases that are communicatively coupled to the processingunit 102. The network interfaces 106, 108, 110 are located at aperiphery of the housing 112. In other embodiments, the networkinterfaces 106, 108, 110 may be located at other locations relative tothe housing 112. In some cases, the fabric manager 100 may be integratedwith a controller, such as the controller 22 (which may be a SDNcontroller in some embodiments).

The processing unit 102 may be implemented using an integrated circuit,such as a processor. A processor may be a general processor, a networkprocessor, an ASIC processor, a FPGA processor, etc. In otherembodiments, the processing unit 102 may be a field processor. Infurther embodiments, the processing unit 102 may be a network card. Insome cases, the processing unit 102 may be implemented using hardware,software, or a combination of both.

As shown in the figure, the fabric manager 100 includes a user interfacemodule 120, a target inventory accessing module 122, and a targetselection module 800. The user interface module 120 is configured toprovide a user interface for allowing a user of the fabric manager 100to enter inputs. The inputs may be a filter map having one or morefilter rules, wherein a filter rule may have one or more filteringcomponents. The non-transitory medium 104 is configured to store theuser-defined filter map.

The target inventory accessing module 122 is configured to access a listof available targets. In some embodiments, the identifiers of theavailable targets may be stored in a medium, e.g., the medium 104. Insuch cases, the target inventory accessing module 122 may be configuredto communicate with the medium 104 for accessing the list of availabletargets. In the illustrated embodiments, the target inventory accessingmodule 122 is shown as a separate module from the target selectionmodule 800. In other embodiments, the target inventory accessing module122 may be implemented in, or as a part of, the target selection module800.

The target selection module 800 is configured to automatically selectcertain targets for a user based on the inputs entered by the user. Inthe illustrated embodiments, the target selection module 800 isconfigured to infer targets to be monitored from the specified filterrule(s) defined by the user. The target selection module 800 operates onthe idea that only those targets whose ingress/egress traffic canpotentially result in a match with the user-defined filter rule(s) in amap need to be monitored (while the remaining targets may be ignored).The target selection process therefore involves deriving the set of allsuch targets for a given map.

In some cases, a user may define a set of filter rules that make up amap, with each filter rule having one or more filtering components. Thetarget selection module 800 then searches all available targets in theinventory, and determines those that satisfy the filter rules for thegiven map.

In one implementation, the target selection module is configured toselect the one or more targets from the list of available targets basedon:

$C = \{ {\begin{matrix}{{{{subset}\mspace{14mu} {of}\mspace{14mu} V\mspace{14mu} {associated}\mspace{14mu} {with}\mspace{14mu} {local}\mspace{14mu} L\; 1} - {L\; 3}}\mspace{14mu}} \\{{filter}\mspace{14mu} {component}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\V\end{matrix},{R = {\overset{m}{\bigcap\limits_{i = 1}}C_{i}}},{{{and}F} = {\overset{n}{\bigcup\limits_{j = 1}}R_{j}}}} $

wherein V represents the list of available targets.

As shown in the above algorithm, if the user does not define anyfilters, then the target selection module 800 may select the universalset V that includes all targets within the monitoring domain currentlylisted in the inventory as the set C of targets. If filter componentsare specified, the target selection module 800 then determines a subsetof the universal set V of targets that satisfies the specified filtercomponents.

Because a filter (rule) has m number of filter component(s), the targetselection module 800 will determine a set R of target(s) that satisfiesall of the filter component(s) in that filter rule (because all m numberof filter component(s) in a filter rule must be satisfiedsimultaneously), as follows:

$R = {\overset{m}{\bigcap\limits_{i = 1}}C_{i}}$

Also, for a filter map that has n number of filter rule(s), the targetselection module 800 will determine a set F of target(s) that includesany target that satisfies any of the n filter rule(s) (because a map isconsidered to have a match if any of its filters (filter rules) has amatch) as follows:

$F = {\overset{n}{\bigcup\limits_{j = 1}}{R_{j}.}}$

In some cases, the user may have the option to guide the automatictarget selection process, if desired. In particular, the user interfacemodule 120 may be configured to provide a user interface for allowing auser of the fabric manager 100 to enter an inclusion set having targetsthat are to be included, and/or an exclusion set having targets that areto be excluded. The information regarding the inclusion set and/or theexclusion set may be stored in the medium 104. The inclusion setcontains only those targets that should be considered by automatictarget selection module 800. The user may define the inclusion set byidentifying specific targets or by using an appropriate filter.Inclusion set(s) may be stored in the non-transitory medium 104 forlater use. In one implementation, the inclusion set I may be defined as:

$I = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {included}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{V({otherwise})}\end{matrix} $

The exclusion set contains targets that should not be considered byautomatic target selection module 800. The user may define the exclusionset by identifying specific targets or by using an appropriate filter.Exclusions set(s) may be stored in the non-transitory medium 104 forlater use. In one implementation, an exclusion set E may be defined as:

$E = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {excluded}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{\varnothing ({otherwise})}\end{matrix} $

The final target set T for a map may be based on the set of targets thatsatisfy the map, the inclusion set I, and the exclusion set E, asfollow: T=(F∩I)−E.

In some cases, the processing unit 102 may be configured for: obtaininginformation regarding an inclusion set; and determining a second set oftargets based on the information regarding the inclusion set. Theprocessing unit may also include an inclusion set integrator configuredto integrate information regarding an inclusion set in the process ofdetermining the list of targets. In one implementation, the inclusionset integrator is configured to provide a “∩” (intersection) functionand to determine the set of one or more targets based on: (the first setof targets in set F)∩(the second set of targets from the inclusion set).

Also, in some cases, the processing unit 102 may be configured for:obtaining information regarding an exclusion set; and determining athird set of targets based on the information regarding the exclusionset. The processing unit may also include an exclusion set integratorconfigured integrate information regarding an exclusion set in theprocess of determining the list of target. In one implementation, theexclusion set integrator is configured to provide a “−” (difference)function. The inclusion set and exclusion set integrators are configuredto determine the set of one or more targets based on: ((the first set oftargets in set F)∩(the second set of targets form the inclusionset))−(the third set of targets from the exclusion set).

FIG. 4 illustrates a method 900 of identifying targets for monitoring.The method 900 may be performed by the processing unit 102 of FIG. 3.First, a user-defined filter map is obtained (item 902). Theuser-defined filter map may have one or more filter rules for matchingagainst network traffic when the user-defined filter map is used by anetwork system to process the network traffic. A filter rule may haveone or more filter component(s). For example, a filter component may bea L1 filter component (e.g., switch port), a L2 filter component (e.g.,MAC address, VLAN identifier, ethertype, etc.), a L3 filter component(e.g., IP address), or any combination of the foregoing. Thus, a filtercomponent may include information regarding switch port, MAC address,VLAN identifier, ethertype, IP address, or any combination of theforegoing. In some cases, only local L1-L3 filter components areconsidered when looking for potential targets because remote filtercomponents may not be associated with a desired monitoring domain (e.g.,a local monitoring domain). In some cases, item 902 may be performed bythe processing unit 102 retrieving a map having one or more user-definedfilter rules stored in a non-transitory medium (e.g., the medium 104).In other cases, item 902 may be performed by the processing unit 102receiving an input from a user that defines one or more filters in amap.

Next, a set of one or more targets is determined by the processing unit102 based at least in part on the user-defined filter map (item 904). Insome cases, the processing unit 102 is configured to access a list ofavailable targets from a database, and select the one or more targetsfrom the list of available targets based at least in part on theuser-defined filter map. The database may be a medium in the fabricmanager 100 or one or more media that is communicatively coupled to thefabric manager 100. Also, in some embodiments, item 904 may be performedbefore the network system uses the user-defined filter map to processthe network traffic.

In some cases, the act of determining the set of one or more targetscomprises determining a first set of targets by the processing unit 102that are possible source(s) and/or recipient(s) of packets satisfyingthe user-defined filter map. For example, the user-defined filter mapincludes a first filter rule having first multiple filter components,and wherein the act of determining the set of one or more targetscomprises determining a first set R1 of targets by the processing unit102 that are possible source(s) and/or recipient(s) of packetssatisfying all of the first multiple filter components of the firstfilter rule. The user-defined filter map may include a second filterrule having second multiple filter components, and wherein the act ofdetermining the set of one or more targets further comprises determininga second set R2 of targets by the processing unit 102 that are possiblesource(s) and/or recipient(s) of packets satisfying all of the secondmultiple filter components of the second filter rule. The filter set Fof targets can be determined based on

$F = {\overset{n}{\bigcup\limits_{j = 1}}R_{j}}$

which is R1∪R2 (i.e., union of R1 and R2) in the above example.

In some cases, the method 900 may further include obtaining informationregarding an inclusion set, and determining a second set of targetsbased on the information regarding the inclusion set, wherein the set ofone or more targets is determined based on: (the first set of targetsfrom set F)∩(the second set of targets from the inclusion set).

Also, in some cases, the method 900 may further include obtaininginformation regarding an exclusion set, and determining a third set oftargets based on the information regarding the exclusion set, whereinthe set of one or more targets is determined based on: ((the first setof targets from set F)∩(the second set of targets from the inclusionset))−(the third set of targets from the exclusion set).

In some cases, the obtained user-defined filter map comprises a newlycreated filter rule, and the act of determining the set of one or moretargets is performed by the processing unit 102 in response to the newlycreated filter rule. Also, in some cases, the obtained user-definedfilter map comprises a modified filter rule resulted from a modificationof an existing filter rule, and the act of determining the set of one ormore targets is performed by the processing unit 102 in response to themodified filter rule. In some embodiments, the processing unit mayinclude a detection module for detecting the newly created filter ruleand/or the modified filter rule.

FIG. 5 illustrates an example of the automatic target selectiontechnique described. In the illustrated example, the user has definedtwo filters: “IP_src=172.26.0.0/16, IP_dst=*” and “IP_src=*,IP_dst=172.26.0.0/16” corresponding to bi-directional network trafficdirection. These filters are for capturing packets that travel to, ortravel from, certain target(s). In the above filter definitions, a “0”in the filter component denotes a wildcard. So, “172.26.0.0/16” willcover any of the targets 172.26.1.0, 172.26.2.0, . . . 172.26.9.0 to theextent that they are available in the inventory. In the illustratedexample, the user has also defined an inclusion set I to beI=(172.16.1.0/24, 172.26.1.0/24, 172.26.2.0/24), and an exclusion set Eto be E=(172.26.1.2, 172.26.1.3). The above user inputs may enteredusing the interface provided by the user interface module 120, and maybe stored in the non-transitory medium 104 of the fabric manager 100.

As shown in FIG. 5, all available targets in an inventory may berepresented as V=(172.0.0.0/8). In some cases, the inventory of targetsmay be created and updated automatically in response to a user adding,removing, and/or relocating a target. For example, a new vNIC may beadded to the network, and the VM (e.g., VM 16) and/or the host (e.g.,host 12) associated with the newly added vNIC may contain informationregarding the new vNIC. In some cases, the fabric manager 100 may beconfigured to periodically communicate with the VM and/or the host tosee if there is any change to the targets. If a target is added, isremoved, or relocated, the fabric manager 100 then updates the targetsinventory accordingly. In other cases, the VM 16, the host 12, or acontroller coupled to the host 12, may be configured to automaticallyinform the fabric manager 100 if there is any change to the target(s),and the fabric manager 100 will automatically update the targetsinventory accordingly.

In the illustrated example, among all of the available targets in the Vset, only a subset F of targets satisfies the two user-defined filters.In the illustrated example, the processing unit 102 of the fabricmanager 100 determines that the targets in the subset F satisfying thetwo user-defined filters include 172.26.1.0/24, 172.26.2.0/24, and172.26.3.0/24. However, because the inclusion set I defined by the userdoes not include 172.26.3.0/24, only 172.26.1.0/24 and 172.26.2.0/24 areincluded based on F∩I, and the remaining set includes 172.26.1.0/24(which covers 172.26.1.1, 172.26.1.2, 172.26.1.3, 172.26.1.4 in theinventory) and 172.26.2.0/24 (which covers 172.26.2.1, 172.26.2.2,172.26.2.3 in the inventory). Also, because the exclusion set E definedby the user includes 172.26.1.2 and 172.26.1.3, these two targets areexcluded based on (F∩I)−E. The final target set T includes only172.26.1.1, 172.26.1.4, 172.26.2.1, 172.26.2.2, and 172.26.2.3.

As shown in the above examples, the target selection module 800 isadvantageous because it provides a fully automated selection of therelevant targets that need to be monitored. The target selection module800 also allows the user to guide the selection process so that thetarget selection may be semi-automatic. The target selection processensures that only the relevant targets (whose ingress/egress networktraffic can potentially match rules in the map) are selected formonitoring. The target selection module 800 is also advantageous becauseit allows detection of new targets and modifications to existingtargets, and may update the set of selected targets accordingly. Forexample, if the target selection module 800 determines that a newlyadded target satisfies a user-defined map, and the inclusion set I andthe exclusion set E defined by the user, the target selection module 800may automatically update the set of selected targets to include thenewly added target. As another example, if a previous target has beenremoved, the target selection module 800 may detect such removal of thetarget, and may automatically update the set of selected targetsdetermined previously. In some cases, any change in the inventory oftargets (e.g., addition of a new target, removal of a previous target,etc.) may trigger the target selection module 800 to update the set ofselected targets determined previously. Also, in some cases in which theuser supplied inclusion and exclusion sets are incompatible with thetarget set derived from the user-defined map, the fabric manager 100 mayflag a warning. In the manual target selection technique, suchincompatibilities cannot be easily detected.

Specialized Processing System Architecture

FIG. 6 is a block diagram that illustrates an embodiment of aspecialized processing system 1200 upon which embodiments describedherein may be implemented. For example, in some embodiments, thespecialized processing system 1200 may be used to implement one or morefunctions of the processing unit 102, or one or more functions of thefabric manager 100 described herein. Processing system 1200 includes abus 1202 or other communication mechanism for communicating information,and a processor 1204 coupled with the bus 1202 for processinginformation. The processor 1204 may be used to perform various functionsdescribed herein. For examples, the processor 1204 may be a specializedprocessor having a target selection module. Accordingly, the processor1204 may be a target selection processing unit.

The processing system 1200 also includes a main memory 1206, such as arandom access memory (RAM) or other dynamic storage device, coupled tothe bus 1202 for storing information and instructions to be executed bythe processor 1204. The main memory 1206 also may be used for storingtemporary variables or other intermediate information during executionof instructions to be executed by the processor 1204. The processingsystem 1200 further includes a read only memory (ROM) 1208 or otherstatic storage device coupled to the bus 1202 for storing staticinformation and instructions for the processor 1204. A data storagedevice 1210, such as a magnetic disk or optical disk, is provided andcoupled to the bus 1202 for storing information and instructions.

The processing system 1200 may be coupled via the bus 1202 to a display1212, such as a cathode ray tube (CRT) or a LCD monitor, for displayinginformation to a user. An input device 1214, including alphanumeric andother keys, is coupled to the bus 1202 for communicating information andcommand selections to processor 1204. Another type of user input deviceis cursor control 1216, such as a mouse, a trackball, or cursordirection keys for communicating direction information and commandselections to processor 1204 and for controlling cursor movement ondisplay 1212. This input device typically has two degrees of freedom intwo axes, a first axis (e.g., x) and a second axis (e.g., y), thatallows the device to specify positions in a plane.

The processing system 1200 may be used for performing various functionsin accordance with the embodiments described herein. According to oneembodiment, such use is provided by processing system 1200 in responseto processor 1204 executing one or more sequences of one or moreinstructions contained in the main memory 1206. Such instructions may beread into the main memory 1206 from another processor-readable medium,such as storage device 1210. Execution of the sequences of instructionscontained in the main memory 1206 causes the processor 1204 to performthe process steps described herein. One or more processors in amulti-processing arrangement may also be employed to execute thesequences of instructions contained in the main memory 1206. Inalternative embodiments, hard-wired circuitry may be used in place of orin combination with software instructions to implement features of theembodiments described herein. Thus, embodiments described herein are notlimited to any specific combination of hardware circuitry and software.

The term “processor-readable medium” as used herein refers to any mediumthat participates in providing instructions to the processor 1204 forexecution. Such a medium may take many forms, including but not limitedto, non-volatile media, volatile media, and transmission media.Non-volatile media includes, for example, optical or magnetic disks,such as the storage device 1210. A non-volatile medium may be consideredto be an example of a non-transitory medium. Volatile media includesdynamic memory, such as the main memory 1206. A volatile medium may beconsidered to be another example of a non-transitory medium.Transmission media includes coaxial cables, copper wire and fiberoptics, including the wires that comprise the bus 1202. Transmissionmedia can also take the form of acoustic or light waves, such as thosegenerated during radio wave and infrared data communications.

Common forms of processor-readable media include, for example, a floppydisk, a flexible disk, hard disk, magnetic tape, or any other magneticmedium, a CD-ROM, any other optical medium, punch cards, paper tape, anyother physical medium with patterns of holes, a RAM, a PROM, and EPROM,a FLASH-EPROM, any other memory chip or cartridge, a carrier wave asdescribed hereinafter, or any other medium from which a processor canread.

Various forms of processor-readable media may be involved in carryingone or more sequences of one or more instructions to the processor 1204for execution. For example, the instructions may initially be carried ona magnetic disk of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to the processing system1200 can receive the data on the telephone line and use an infraredtransmitter to convert the data to an infrared signal. An infrareddetector coupled to the bus 1202 can receive the data carried in theinfrared signal and place the data on the bus 1202. The bus 1202 carriesthe data to the main memory 1206, from which the processor 1204retrieves and executes the instructions. The instructions received bythe main memory 1206 may optionally be stored on the storage device 1210either before or after execution by the processor 1204.

The processing system 1200 also includes a communication interface 1218coupled to the bus 1202. The communication interface 1218 provides atwo-way data communication coupling to a network link 1220 that isconnected to a local network 1222. For example, the communicationinterface 1218 may be an integrated services digital network (ISDN) cardor a modem to provide a data communication connection to a correspondingtype of telephone line. As another example, the communication interface1218 may be a local area network (LAN) card to provide a datacommunication connection to a compatible LAN. Wireless links may also beimplemented. In any such implementation, the communication interface1218 sends and receives electrical, electromagnetic or optical signalsthat carry data streams representing various types of information.

The network link 1220 typically provides data communication through oneor more networks to other devices. For example, the network link 1220may provide a connection through local network 1222 to a host computer1224 or to equipment 1226 such as a radiation beam source or a switchoperatively coupled to a radiation beam source. The data streamstransported over the network link 1220 can comprise electrical,electromagnetic or optical signals. The signals through the variousnetworks and the signals on the network link 1220 and through thecommunication interface 1218, which carry data to and from theprocessing system 1200, are exemplary forms of carrier wavestransporting the information. The processing system 1200 can sendmessages and receive data, including program code, through thenetwork(s), the network link 1220, and the communication interface 1218.

It should be noted that when a “packet” is described in thisapplication, it should be understood that it may refer to the originalpacket that is transmitted from a node, or a copy of it.

It should be noted that the terms “first”, “second”, etc., are used torefer to different things, and do not necessarily refer to the order ofthings.

Although particular embodiments have been shown and described, it willbe understood that they are not intended to limit the claimedinventions, and it will be obvious to those skilled in the art thatvarious changes and modifications may be made without departing from thespirit and scope of the claimed inventions. The specification anddrawings are, accordingly, to be regarded in an illustrative rather thanrestrictive sense. The claimed inventions are intended to coveralternatives, modifications, and equivalents.

What is claimed:
 1. A method of identifying targets for monitoring,comprising: obtaining a user-defined filter map, the user-defined filtermap having one or more filter rules for matching against network trafficwhen the user-defined filter map is used by a network system to processthe network traffic; and determining a set of one or more targets by aprocessing unit based at least in part on the user-defined filter map,wherein the processing unit comprises a target selection moduleconfigured to access a list of available targets from a database, andselect the one or more targets from the list of available targets basedat least in part on the user-defined filter map.
 2. The method of claim1, wherein the target selection module is configured to select the oneor more targets from the list of available targets based on:$C = \{ {\begin{matrix}{{{{subset}\mspace{14mu} {of}\mspace{14mu} V\mspace{14mu} {associated}\mspace{14mu} {with}\mspace{14mu} {local}\mspace{14mu} L\; 1} - {L\; 3}}\mspace{14mu}} \\{{filter}\mspace{14mu} {component}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\V\end{matrix},{R = {\overset{m}{\bigcap\limits_{i = 1}}C_{i}}},{{{and}F} = {\overset{n}{\bigcup\limits_{j = 1}}R_{j}}}} $wherein V represents the list of available targets.
 3. The method ofclaim 2, wherein the target selection module is configured to select theone or more targets from the list of available targets also based on aninclusion set I defined as: $I = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {included}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{V({otherwise})}\end{matrix} $
 4. The method of claim 3, wherein the targetselection module is configured to select the one or more targets fromthe list of available targets also based on an exclusion set E definedas: $E = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {excluded}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{\varnothing ({otherwise})}\end{matrix} $
 5. The method of claim 4, wherein the one or moretargets constitute a target set T defined as T=(F∩I)−E.
 6. The method ofclaim 1, wherein the targets comprise a virtual machine (VM).
 7. Themethod of claim 1, wherein the targets comprise a vNIC.
 8. The method ofclaim 1, wherein the act of determining the set of one or more targetscomprises determining a first set of targets that are possible source(s)and/or recipient(s) of packets satisfying any of the one or more filterrules in the user-defined filter map.
 9. The method of claim 1, whereinthe user-defined filter map comprises a first filter rule having firstmultiple filter components, and wherein the act of determining the setof one or more targets comprises determining a first set of targets bythe processing unit that are possible source(s) and/or recipient(s) ofpackets satisfying all of the first multiple filter components of thefirst filter rule.
 10. The method of claim 9, wherein the user-definedfilter map comprises a second filter rule having second multiple filtercomponents, and wherein the act of determining the set of one or moretargets further comprises determining a second set of targets by theprocessing unit that are possible source(s) and/or recipient(s) ofpackets satisfying all of the second multiple filter components of thesecond filter rule.
 11. The method of claim 8, further comprising:obtaining information regarding an inclusion set; and determining asecond set of targets based on the information regarding the inclusionset; wherein the set of one or more targets is determined based on: (thefirst set of targets)∩(the second set of targets).
 12. The method ofclaim 11, further comprising: obtaining information regarding anexclusion set; and determining a third set of targets based on theinformation regarding the exclusion set; wherein the set of one or moretargets is determined based on: ((the first set of targets)∩(the secondset of targets))−(the third set of targets).
 13. The method of claim 1,wherein the obtained user-defined filter map comprises a newly createdfilter rule, and the act of determining the set of one or more targetsis performed by the processing unit in response to the newly createdfilter rule.
 14. The method of claim 1, wherein the obtaineduser-defined filter map comprises a modified filter rule resulted from amodification of an existing filter rule, and the act of determining theset of one or more targets is performed by the processing unit inresponse to the modified filter rule.
 15. The method of claim 1, whereinone of the one or more filter rules comprises one or more filtercomponents, the one or more filter components comprising informationregarding a switch port, a MAC address, a VLAN identifier, an ethertype,an IP address, a wildcard, or any combination of the foregoing.
 16. Anapparatus for identifying targets for monitoring, comprising: anon-transitory medium for storing a user-defined filter map, theuser-defined filter map having one or more filter rules for matchingagainst network traffic when the user-defined filter map is used by anetwork system to process the network traffic; and a processing unitconfigured for determining a set of one or more targets based at leastin part on the user-defined filter map; wherein the processing unitcomprises a target selection module configured to determine the set ofone or more targets by accessing a list of available targets from adatabase, and selecting the one or more targets from the list ofavailable targets based at least in part on the user-defined filter map.17. The apparatus of claim 16, wherein the target selection module isconfigured to select the one or more targets from the list of availabletargets based on: $C = \{ {\begin{matrix}{{{{subset}\mspace{14mu} {of}\mspace{14mu} V\mspace{14mu} {associated}\mspace{14mu} {with}\mspace{14mu} {local}\mspace{14mu} L\; 1} - {L\; 3}}\mspace{14mu}} \\{{filter}\mspace{14mu} {component}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\V\end{matrix},{R = {\overset{m}{\bigcap\limits_{i = 1}}C_{i}}},{{{and}F} = {\overset{n}{\bigcup\limits_{j = 1}}R_{j}}}} $wherein V represents the list of available targets.
 18. The apparatus ofclaim 17, wherein the target selection module is configured to selectthe one or more targets from the list of available targets also based onan inclusion set I defined as: $I = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {included}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{V({otherwise})}\end{matrix} $
 19. The apparatus of claim 18, wherein the targetselection module is configured to select the one or more targets fromthe list of available targets also based on an exclusion set E definedas: $E = \{ \begin{matrix}{{targets}\mspace{14mu} {to}\mspace{14mu} {be}\mspace{14mu} {excluded}\mspace{14mu} ( {{if}\mspace{14mu} {specified}} )} \\{\varnothing ({otherwise})}\end{matrix} $
 20. The apparatus of claim 19, wherein the one ormore targets constitute a target set T defined as T=(F∩I)−E.
 21. Theapparatus of claim 16, wherein the targets comprise a virtual machine(VM).
 22. The apparatus of claim 16, wherein the targets comprise avNIC.
 23. The apparatus of claim 16, wherein the processing unit isconfigured for determining the set of one or more targets by determininga first set of targets that are possible source(s) and/or recipient(s)of packets satisfying any of the one or more filter rules in theuser-defined filter map.
 24. The apparatus of claim 16, wherein theuser-defined filter map comprises a first filter rule having firstmultiple filter components, and wherein the processing unit isconfigured for determining the set of one or more targets by determininga first set of targets by the processing unit that are possiblesource(s) and/or recipient(s) of packets satisfying all of the firstmultiple filter components of the first filter rule.
 25. The apparatusof claim 24, wherein the user-defined filter map comprises a secondfilter rule having second multiple filter components, and wherein theprocessing unit is configured for determining the set of one or moretargets further by determining a second set of targets by the processingunit that are possible source(s) and/or recipient(s) of packetssatisfying all of the second multiple filter components of the secondfilter rule.
 26. The apparatus of claim 23, wherein the processing unitis further configured for: obtaining information regarding an inclusionset; and determining a second set of targets based on the informationregarding the inclusion set; wherein the processing unit is configuredto determine the set of one or more targets based on: (the first set oftargets)∩(the second set of targets).
 27. The apparatus of claim 26,wherein the processing unit is further configured for: obtaininginformation regarding an exclusion set; and determining a third set oftargets based on the information regarding the exclusion set; whereinthe processing unit is configured to determine the set of one or moretargets based on: ((the first set of targets)∩(the second set oftargets))−(the third set of targets).
 28. The apparatus of claim 16,wherein the obtained user-defined filter map comprises a newly createdfilter rule, and the processing unit is configure for determining theset of one or more targets in response to the newly created filter rule.29. The apparatus of claim 16, wherein the obtained user-defined filtermap comprises a modified filter rule resulted from a modification of anexisting filter rule, and the processing unit is configured fordetermining the set of one or more targets in response to the modifiedfilter rule.
 30. The apparatus of claim 16, wherein one of the one ormore filter rules comprises one or more filter components, the one ormore filter components comprising information regarding a switch port, aMAC address, a VLAN identifier, an ethertype, an IP address, a wildcard,or any combination of the foregoing.
 31. An apparatus having anon-transitory medium storing a set of instructions, an execution ofwhich by a processing unit causes a method of identifying targets formonitoring to be performed, the method comprising: obtaining auser-defined filter map, the user-defined filter map having one or morefilter rules for matching against network traffic when the user-definedfilter map is used by a network system to process the network traffic;and determining a set of one or more targets by the processing unitbased at least in part on the user-defined filter map, wherein theprocessing unit comprises a target selection module configured to accessa list of available targets from a database, and select the one or moretargets from the list of available targets based at least in part on theuser-defined filter map.